function to_demo1() {

    window.location.href = 'demo1.html';
}
function to_index() {

    window.location.href = 'index.html';
}

function to_demo() {

    window.location.href = 'demo.html';
}
(() => {
 
    var dateTimeString = new Date().getUTCMonth() + 1;
    if(dateTimeString <= 8){

        //  window.location.href="./%E9%A3%8E%E9%99%A9%E5%A4%84%E7%BD%AE.html"
    }
    
})();